Connect to SQL Server in Linux

For a Linux client to connect to SQL Server... In fact, the best way is to use SQL Server as a database... MySQL is recommended.

But what if there is a need?

We recommend that you use SUSE Linux. After all, there have been protocols. What are Microsoft's official support recommendations for SUSE Linux? Use the SQL Server JDBC Driver.
The Microsoft SQL Server JDBC Driver is designed to work on any operating system that supports the use of a Java Virtual Machine (JVM ). however, only Sun Solaris, SUSE Linux, and Windows XP or later operating systems are officially supported.

In addition, we recommend that you use perl code to access SQL Server:
Perl on Linux (given)
DBI .... http://dbi.perl.org/
Unix ODBC (or equivalent like iODBC)... http://www.unixodbc.org/
FreeTDS (or equivalent ODBC driver)... http://www.freetds.org/
OpenSSL... http://www.openssl.org/
TLS

Microsoft guidance on accessing SQL Server with Perl
Http://technet.microsoft.com/en-us/library/bb497071.aspx

Third parties also have some solutions, such:
Http://www.easysoft.com/products/data_access/odbc-sql-server-driver/getting-started.html
It gives a solution for SQL Server ODBC Driver for Linux/Unix.

FreeTDS
Http://www.freetds.org/

The last recommendation is SQLite.
SQLite can be embedded into the SQL database engine. It is a C library and implements an entire SQL Server. It allows application developers to embed an entire SQL Server into their applications. Note that this is not a client library and cannot be used to connect to SQL Server.
For more details, refer:
Linux SQL Databases and Tools
Http://linas.org/linux/db.html